The present invention relates to a high reliability optical fiber splice protector and a method for applying the protector to the splice. More specifically, the invention provides for protecting a splice between a first optical fiber and a second optical fiber where the first optical fiber and the second optical fiber are contained in jackets or coatings of dissimilar diameters.
A currently known method for protecting a splice between optical fibers that are contained within jackets of dissimilar diameters utilizes a splint which is applied over the splice and which extends from the jacket of one fiber to the jacket of the other fiber. FIG. 1 illustrates a splice 100 between two fibers that are contained within jackets of different diameters. As illustrated, fiber 110 is spliced to fiber 120. Fiber 110 is contained in jacket 112, which has a larger outside diameter than jacket 122, which contains fiber 120. As is shown in FIG. 2, the currently known method for protecting the splice utilizes a splint 130 that extends from the larger diameter jacket 112 to the smaller diameter jacket 122. No accommodation is made when applying the splint for the difference in the diameters of jackets 112 and 122.
This method of protecting the splice presents drawbacks, especially if the spliced fibers are utilized in a high reliability fiber optic communication system where strength of the splice and the protector are of significant importance. Because of the difference in the diameters of the jackets, forces may not be equally applied across the splice and thus greater stresses may be applied to the splice. Additionally, handling of the spliced fiber is made more difficult. For example, if the spliced fiber is coiled, e.g., for storage purposes, a kink may develop in the coiled fiber resulting in damage to the splice and/or fiber. Therefore, whereas the above-described method for protecting a splice may be adequate for use in some types of fiber optic communications systems, e.g., a terrestrial-based system, it is not adequate for use in a high reliability system, such as a submarine, or undersea, fiber optic transmission system, where the reliability requirement is typically 25 years. Submarine systems are generally subjected to greater stresses than terrestrial systems during installation and are not easily accessible once installed.
An additional drawback with the known methodology is related to the method of applying the splice protector to the splice. Currently, when applying the splice protector, testing of the splice is conducted after the protective splint has been applied over the splice. The testing is directed to determining the loss characteristics of the splice after the splint has been applied and only indirectly tests the strength of the splice itself. Because the systems that the splice is employed in are not usually stressed to the extent that a high reliability system is stressed, the strength of the splice itself is not of prime concern. Therefore, the splice is only tested for light transmittance and strength after the splint is applied. However, this method of testing the splice, i.e., after the splint has been applied, does not test all of the characteristics of the splice that are of importance if the splice is to be utilized in a high reliability system, namely the strength of the splice itself before the splint is applied. Therefore, it would be desirable to provide for a method of applying a splice protector that tests characteristics of the splice that are of importance when the splice is used in a high reliability system.
As addressed above, the currently known method for protecting a splice between fibers contained in dissimilar jackets presents drawbacks if the splice is to be utilized in a high reliability system. Therefore, it would be desirable to provide for a highly reliable optical fiber splice protector and a method for applying the splice protector to the splice.
The drawbacks in the prior art are overcome by the present invention for a high reliability optical fiber splice protector and a method for applying the protector. In accordance with an embodiment of the present invention, an optical fiber splice protector for protecting a splice between a first optical fiber and a second optical fiber is provided. The first optical fiber includes a first fiber coating and the second optical fiber includes a second fiber coating where the second fiber coating has a larger diameter than the first fiber coating. The splice protector includes a sleeve that is applied around the first fiber coating. The sleeve has a similar diameter to the diameter of the second fiber coating. A splint is applied around the splice of the first optical fiber and the second optical fiber and extends from the sleeve to the second fiber coating.
Additionally, a method for applying a fiber optic splice protector to a spliced fiber is provided. The method includes the steps of positioning the splint around the splice, proof testing the splice, and heat curing the splint around the splice after proof testing of the splice.
In this manner, the present invention provides for a fiber optic splice protector for protecting a splice between fibers contained in dissimilar jackets and a method for applying a splice protector. The present invention has particular utility for use in high reliability systems, such as submarine fiber optic communication systems.